Improved metallic-plate screen for screening paper-pulp



A. ST. 0. WINCHESTER; METALLIC PLATE SCREEN FOR SCREENING PAPER PULP. No. 105,755. Patented July 26, 1870..

Fig t UNITED STATES PATENT OFFIC ARTHUR ST. CLAIR WINCHESTER, OF BOSTON, MASSACHUSETTS, ASSIGI IOR TO HIMSELF AND JAMES SETON PARSONS, OE SAME PLACE.

IMPROVED METALLIC-PLATE SCREEN rots'omarn'me' PAPER-PULP.

Specification forming part of Letters Patent- No. 105,755, dated July 26, 1570.

transverse section, of it. Fig. 4 is a section on an enlarged scale of a part of the plate, showing two or more of its slits with the j-plating in its arrangement with reference to. them.

On Marchfl, 1869, Letters Patent No. 87,385 were granted to myself and James S. Parsons on an improved metallic-plate screen for screening paper-pulp, such havingoeen invented by me. The process'clai mcd' and ded by me in the specification of such pat cut consisted in first sawing or making each of the slits of the metallic or brass body or plate of the screen by a tool or saw, and subsequently depositing on the opposite sides of -such slit, or on the same and the external surface or surfaces of the plate, a metallic plating by means of an electroplating-bath and an electric current and battery. Since that invention was made and patented I have discovered a better and cheaper method of making a pulp-screen with a resisting plating of copper. I have found that brass, of which the body of suchscreens is made, by being composed of two 1netals.zinc and copper has the zinc not uniformly distributed throughout the copper, and that inconsequence of this while the screen is in use the'wear of the I edges of the slits is very uneven, as they are not of uniform induration. I have also discovered that by applying to the upper surface of the brass plate, before the slits are cut in it, a thin layer of copper by means of an electroplating-bath and a battery connected 7 therewith, or, in other words, by electroplating the upper surfaceof the metallic. plate with copper, I am enabled to provide thesurfacewith a homogeneous plating which, by.

covering the plate at the upper parts of the edges of each slit, will answer all' necessary purposes-of protecting the slit from uneven wear. After the plate may have been so treated or prepared, the slits are to be cut in it and through the homogeneous plating. My present invention saves the necessity of applying the coating of copper to the opposite inner .sides of each of the slits, thereby diminishing the width of the slits when it may not be desirable so to do. With my former, invention the slits were made in the brass plate before it.was electroplated with copper;

consequently they were not cut through the copper; but with my present invention or improvement I not only prepare the plating first, and only on the upper surface of the plate, but I afterward cut the slits through both the copper plating and the brass body or plate. I \Vhat, therefore, I claim-as my new inyention is 1. The combining with the plate by the electroplating process a homogeneous metallic or copper coating applied to' one face of it,

and subsequently sawing or cutting each of the slits through such coating and the plate. 2. The improved manufacture or paper-*- pulpscr'een as made by combining withai metallic or brass plate a homogeneous coat ing of resisting metal or copper applied to its upper surface by the electroplating process, and subsequently cutting the slits through such coating and plate, the whole being sub stantially as set forth.

ARTHUR sr. CLAIR wmcntsrna.

Witnesses: I

R. H. EDDY, S. N. PIPER. 

